The deal comes just a day after Aaron Donald set a new high mark for defensive players, signing a similar six-year extension with the Los Angeles Rams worth $US135 million that included $US87 million in guaranteed money.

Mack was the centrepiece of the Raiders defence and comes to the Bears in the midst of an offseason spending spree in Chicago that has brought in talent including wide receivers Allen Robinson and Taylor Gabriel and tight end Trey Burton. Chicago gave up two first-round draft picks in order to bring Mack to the Bears, and with the extension, made clear that they don’t want the perennial Pro-Bowler leaving any time soon.

The Bears open the season on September 6 with a trip to Lambeau Field to take on the Green Bay Packers.